LG EF9500 Semi-Idle based dimming?
[SOLVED -- see the post at the bottom]
I'm a new owner of an LG 65EF9500. The display is connected to my desktop as the primary (and only) display. I do normal stuff on there (work, email, browse, etc). I've noticed a very disturbing effect having to do with some sort of idle based auto-dimming of the display over a very short period of time (4 minutes).
I can be sitting there reading emails and it gradually goes dark, even though I'm clicking around. It did it while I was typing this.
As soon as there is significant activity, like switching to a different window, it goes bright again. The content of the other window seems to be irrelevant. I've switched to windows that are overall brighter or darker, but the effect is the same: the display brightness goes up.
I've looked at most of the posts in the owner's thread and the specific one titled "How to turn off auto-dimming on LG EF9500??" and tried the settings (contrast 67, oled light 40), but is still happens.
This doesn't look like APL (average picture level)/ABL (auto-brightness limiter) to me; I can see the effect of APL/ABL and it doesn't really bother me. From the experiments I've run (which you can try for yourself), I'm guessing that the display looks at the total light output over time and if the total light output is not changing for about 3-4 minutes, even if the image is changing, it starts to dim the display.
It's not from the PC because there is definitely mouse/keyboard activity there and the same PC connected to an LCD never does this.
This is driving me mad, so I've devised a simple reproducible experiment to show the effect. Can someone verify so I know I'm not crazy? Any suggestions how to fix this? Any ideas why this was programmed in?
Here are my settings:
WebOS version: 04.20.08 -- had to upgrade via USB from 04.20.07, as it wouldn't find it automatically. Also happens with 04.20.07
Input assignment on HDMI 1: PC (seleted via the wizard, so it has a the PC icon, not just a name)
Picture mode: Game (User)
Energy Saving: off
OLED Light: 40 (I prefer 50, but it happens at 40)
Color Temp: C30
Advanced controls: everything off. Gamma High1
Picture controls: everything off. Black high. Also happens on Black low.
3D Settings off
Dual Play off
HDMI ULTRA HD Deep Color: on (for HDMI 1)
General -> Power Saving Mode : off
Experiment one: semi-idle dimming
Setup: start with a blank desktop and create two simple windows (e.g. notepad) about 1/4 of the width/height of the screen. See the attached screenshot. Let's call the left window "WindowOne" and the right one "WindowTwo".
Control: Minimize and restore WindowTwo several times to convince yourself that this particular action does not create a sudden large shift in brightness of the entire display.
Run: start the run with WindowOne on the desktop and WindowTwo minimized to the taskbar. For the next 4 minutes, move WindowOne to somewhere else on the screen every 10 seconds. I typically just move the window down and then up by 1/2 a screen. (Make sure you stay away from the edges of the screen that trigger the snap behavior in Windows 7). During these 4 minutes, the display starts to get dimmer. At the end of the run, restore WindowTwo. This will cause the display to suddenly "wake up" and become as bright as it was 4 minutes ago.
Expermient two: specific activity that prevents the dimming.
Setup: exactly as Experiment one.
Control: exactly as Experiment one.
Run: start the run with WindowOne on the desktop and WindowTwo minimized to the taskbar. For the next 4 minutes, alternately, minimize or restore WindowOne every 10 seconds. At the end of the run, restore both windows. There will be no drastic shift in total brightness.
Last edited by bigpc; 11-07-2015 at 10:29 AM.